Fix compat issue with Type.IsAssignableFrom

Signed-off-by: dotnet-bot <dotnet-bot@microsoft.com>
dotnet · Oct 4, 2018 · f420707 · f420707
1 parent d4e9306
commit f420707
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/src/Common/src/CoreLib/System/Type.Helpers.cs b/src/Common/src/CoreLib/System/Type.Helpers.cs
@@ -342,7 +342,7 @@ public virtual bool IsAssignableFrom(Type c)
             // For backward-compatibility, we need to special case for the types
             // whose UnderlyingSystemType are runtime implemented. 
             Type toType = this.UnderlyingSystemType;
-            if (toType.IsRuntimeImplemented())
+            if (toType?.IsRuntimeImplemented() == true)
                 return toType.IsAssignableFrom(c);
 
             // If c is a subclass of this class, then c can be cast to this type.